U.S. patent application number 15/124900 was filed with the patent office on 2017-07-27 for anisotropic conductive film, connection method, and joined body.
This patent application is currently assigned to DEXERIALS CORPORATION. The applicant listed for this patent is DEXERIALS CORPORATION. Invention is credited to Susumu Kumakura, Morio Sekiguchi, Yasunobu Yamada.
Application Number | 20170210947 15/124900 |
Document ID | / |
Family ID | 54071485 |
Filed Date | 2017-07-27 |
United States Patent
Application |
20170210947 |
Kind Code |
A1 |
Yamada; Yasunobu ; et
al. |
July 27, 2017 |
ANISOTROPIC CONDUCTIVE FILM, CONNECTION METHOD, AND JOINED BODY
Abstract
An anisotropic conductive film for anisotropically conductively
connecting a terminal of a first electronic component and a
terminal of a second electronic component, the anisotropic
conductive film including: a conductive particle-containing layer,
which contains an adhesive layer-forming component and conductive
particles, wherein the conductive particle-containing layer has two
endothermic peaks in differential scanning calorimetry where
endothermic peak temperatures are measured under conditions that a
measuring temperature range is from 10.degree. C. to 250.degree. C.
and a heating speed is 10.degree. C./min, and wherein T2 is
30.degree. C. or higher, and T4-T2 is greater than 0.degree. C. but
80.degree. C. or less, where T2 is a temperature of the endothermic
peak present at a lower temperature side, and T4 is a temperature
of the endothermic peak present at a higher temperature side.
Inventors: |
Yamada; Yasunobu;
(Kanuma-shi, Tochigi, JP) ; Sekiguchi; Morio;
(Kanuma-shi, Tochigi, JP) ; Kumakura; Susumu;
(Kanuma-shi, Tochigi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DEXERIALS CORPORATION |
Shinagawa-ku, Tokyo |
|
JP |
|
|
Assignee: |
DEXERIALS CORPORATION
Shinagawa-ku, Tokyo
JP
|
Family ID: |
54071485 |
Appl. No.: |
15/124900 |
Filed: |
February 10, 2015 |
PCT Filed: |
February 10, 2015 |
PCT NO: |
PCT/JP2015/053659 |
371 Date: |
September 9, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08L 75/04 20130101;
H01L 2224/83203 20130101; C09J 2301/304 20200801; C09J 11/04
20130101; H01L 24/29 20130101; C09J 2467/00 20130101; H01L 24/83
20130101; C09J 2475/00 20130101; H01B 1/22 20130101; H01R 4/04
20130101; C08K 2201/001 20130101; C09J 2203/326 20130101; C09J 9/02
20130101; H01L 2224/29439 20130101; H01L 2224/29499 20130101; C09J
7/10 20180101; H01L 2224/83191 20130101; C09J 2301/408 20200801;
C09J 175/04 20130101; C09J 2301/312 20200801; H01L 2224/2929
20130101; C09J 2301/314 20200801; H01L 2224/83193 20130101; H01L
2924/01047 20130101; H01L 2224/2939 20130101; H01B 1/124 20130101;
C09J 167/00 20130101 |
International
Class: |
C09J 7/00 20060101
C09J007/00; C09J 11/04 20060101 C09J011/04; H01B 1/12 20060101
H01B001/12; C09J 9/02 20060101 C09J009/02; H01R 4/04 20060101
H01R004/04; H01L 23/00 20060101 H01L023/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 11, 2014 |
JP |
2014-047154 |
Claims
1. An anisotropic conductive film for anisotropically conductively
connecting a terminal of a first electronic component and a
terminal of a second electronic component, the anisotropic
conductive film comprising: a conductive particle-containing layer,
which contains an adhesive layer-forming component and conductive
particles, wherein the conductive particle-containing layer has two
endothermic peaks in differential scanning calorimetry where
endothermic peak temperatures are measured under conditions that a
measuring temperature range is from 10.degree. C. to 250.degree. C.
and a heating speed is 10.degree. C./min, and wherein T2 is
30.degree. C. or higher, and T4.quadrature.T2 is greater than
0.degree. C. but 80.degree. C. or less, where T2 is a temperature
of the endothermic peak present at a lower temperature side, and T4
is a temperature of the endothermic peak present at a higher
temperature side.
2. The anisotropic conductive film according to claim 1, wherein
the adhesive layer-forming component contains a crystalline
resin.
3. The anisotropic conductive film according to claim 2, wherein
the crystalline resin contains at least two crystalline resins
including a first crystalline resin and a second crystalline
resin.
4. The anisotropic conductive film according to claim 3, wherein
the adhesive layer-forming component further contains an amorphous
resin.
5. The anisotropic conductive film according to claim 1, wherein an
average thickness of the conductive particle-containing layer is
from 80% to 140% relative to an average particle diameter of the
conductive particles.
6. The anisotropic conductive film according to claim 3, wherein a
ratio of a mass of the first crystalline resin to a mass of the
second crystalline resin is from 25:75 to 75:25.
7. The anisotropic conductive film according to claim 4, wherein a
ratio (X):(Y) is from 25:75 to 75:25, where (X) is a sum of a mass
of the first crystalline resin and a mass of the second crystalline
resin and (Y) is a mass of the amorphous resin.
8. The anisotropic conductive film according to claim 4, wherein
the first crystalline resin contains crystalline polyester, the
second crystalline resin contains a crystalline polyurethane resin,
and the amorphous resin contains an amorphous polyester resin.
9. The anisotropic conductive film according to claim 1, wherein an
average particle diameter of the conductive particles is from 2
.mu.m to 40 .mu.m.
10. A connecting method for anisotropically conductively connecting
a terminal of a first electronic component and a terminal of a
second electronic component, the connecting method comprising:
arranging the conductive particle-containing layer of the
anisotropic conductive film according to claim 1 on the terminal of
the second electronic component to perform a first arrangement;
arranging the first electronic component on the conductive
particle-containing layer to bring the terminal of the first
electronic component into contact with the conductive
particle-containing layer to perform a second arrangement; and
heating and pressing the first electronic component with a
heat-press member.
11. The connecting method according to claim 10, wherein a contact
area when the terminal of the first electronic component and the
terminal of the second electronic component are anisotropically
conductively connected is 100 mm2 or greater.
12. A joined structure connected by the connecting method according
to claim 10.
Description
TECHNICAL FIELD
[0001] The present invention relates to an anisotropic conductive
film, a connecting method, and a joined structure.
BACKGROUND ART
[0002] As for the means for connecting electronic parts to each
other, anisotropic conductive films (ACFs) have been conventionally
used.
[0003] The anisotropic conductive film is produced by applying a
resin mixture containing conductive particles onto a release film,
and drying the resin mixture. A method for connecting between
electronic components is a method where the anisotropic conductive
film formed on the release film is placed on one of circuits to be
connected (or both circuits to be connected), the predetermined
temperature and pressure are applied from the side of the release
film to temporarily bond, the release film is peeled, the resultant
is positioned on the other circuit, and the predetermined
temperature and pressure are applied for the predetermined period
to bond (or temporary-bonding may be performed at the predetermined
temperature and pressure for the predetermined period after the
positioning, followed by performing bonding) to thereby perform
electric connection between the circuits.
[0004] In order to improve workability of an assembling step for
electronic components and to enable highly reliable electric
connection in temporary bonding before peeling a release film or
temporary bonding before final bonding, the conductive
particle-containing layer needs to have sufficient adhesion. This
is because the conductive particle-containing layer is peeled off
from a circuit board to be connected when the release film is
peeled, if adhesion of the conductive particle-containing layer in
the anisotropic conductive film is poor. Moreover, the conductive
particle-containing layer and the release film may be peeled off
from each other, for example, when the release film has high
releasability and the anisotropic conductive film is pulled out
from a roll for use. If the releasability of the release film is
poor, the conductive particle-containing layer is peeled off
together with the release film, when the release film is peeled off
after temporary-bonding. Therefore, it is important that the
conductive particle-containing layer and the release film have
appropriate releasability and adhesion.
[0005] Accordingly, there is a need for an anisotropic conductive
film having excellent temporary-fixing properties satisfying the
aforementioned demands at the time of temporary-bonding. For
example, an anisotropic conductive film whose temporary-bonding
properties have been improved by blending a liquid epoxy resin into
a thermoset resin is known (see PTL 1).
[0006] However, the proposed anisotropic conductive film is not
satisfactory in terms of practical use and workability, and needs
further improvements.
[0007] Moreover, there has recently been a demand for connecting
electronic components to each other at a low temperature for a
short period. Therefore, non-reaction-type anisotropic conductive
films that enable to connect electronic components at a low
temperature for a short period have been studied.
[0008] It has been however found that heat resistance of a
non-reaction-type anisotropic conductive film is significantly
impaired, if a liquid material, such as a material used in the
aforementioned thermoset resin anisotropic conductive film, is
blended in the non-reaction-type anisotropic conductive film to
improve temporary-fixing properties. The non-reaction-type
anisotropic conductive film has a problem that a problem associated
with temporary-fixing properties becomes significant.
[0009] Accordingly, there is a need for a non-reaction-type
anisotropic conductive film having excellent temporary-fixing
properties.
[0010] Moreover, anisotropic conductive films have been
conventionally used for connection of fine wirings unsuitable for
solider connection. Since low temperature connection is realized,
anisotropic conductive films have been used for connection of
relatively rough wirings.
[0011] An anisotropic conductive film originally designed for fine
wirings is bonded with a small area, and achieves conduction, as a
conductive particle-containing layer is flown outside a terminal
region by squashing a binder forming the conductive
particle-containing layer to make a thickness of the conductive
particle-containing layer thinner than diameters of conductive
particles, and as a result, the conductive particles are crushed.
In the case where a terminal region of a relative large area is
attempted to be connected, however, a curing reaction is caused at
around a center part of the conductive particle-containing layer of
the large area to increase viscosity before flowing into outside
the terminal region, and thus the conductive particle-containing
layer is not flown outside the terminal region and cannot be made
thin. Therefore, the conductive particles are not crushed
sufficiently, and excellent conduction cannot be obtained.
[0012] On the other hand, non-reaction-type anisotropic conductive
films, which do not carry out a curing reaction, do not increase
viscosity along with a curing reaction. Accordingly, the
non-reaction-type anisotropic conductive films do not have the
aforementioned problem, and can achieve excellent conduction.
[0013] In case of the non-reaction-type anisotropic conductive
films, however, there are problems that tackiness is low and the
aforementioned temporary-fixing properties are poor because the
non-reaction-type anisotropic conductive film contains a
crystalline material having a melting point.
CITATION LIST
Patent Literature
PTL 1 Japanese Patent Application Laid-Open (JP-A) No.
05-154857
SUMMARY OF INVENTION
Technical Problem
[0014] The present invention aims to solve the aforementioned
various problems in the art, and achieve the following object.
Specifically, the present invention has an object to provide an
anisotropic conductive film, which can assure excellent conduction
at a center part of connection, particularly with a relatively
large area, with maintaining sufficient connection resistance, and
has excellent temporary-fixing properties, where a conductive
particle-containing film contained in the anisotropic conductive
film has sufficient adhesion to a substrate that is a target for
connection, and the conductive particle-containing layer and a
release film have sufficient releasability and adhesion, as well as
providing a connecting method and a joined structure both using the
anisotropic conductive film.
Solution to Problem
[0015] The means for solving the aforementioned problems as
follows:
<1> An anisotropic conductive film for anisotropically
conductively connecting a terminal of a first electronic component
and a terminal of a second electronic component, the anisotropic
conductive film including:
[0016] a conductive particle-containing layer, which contains an
adhesive layer-forming component and conductive particles,
[0017] wherein the conductive particle-containing layer has two
endothermic peaks in differential scanning calorimetry where
endothermic peak temperatures are measured under conditions that a
measuring temperature range is from 10.degree. C. to 250.degree. C.
and a heating speed is 10.degree. C./min, and
[0018] wherein T2 is 30.degree. C. or higher, and T4-T2 is greater
than 0.degree. C. but 80.degree. C. or less, where T2 is a
temperature of the endothermic peak present at a lower temperature
side, and T4 is a temperature of the endothermic peak present at a
higher temperature side.
<2> The anisotropic conductive film according to <1>,
wherein the adhesive layer-forming component contains a crystalline
resin. <3> The anisotropic conductive film according to
<2>, wherein the crystalline resin contains at least two
crystalline resins including a first crystalline resin and a second
crystalline resin. <4> The anisotropic conductive film
according to <3>, wherein the adhesive layer-forming
component further contains an amorphous resin. <5> The
anisotropic conductive film according to any one of <1> to
<4>, wherein an average thickness of the conductive
particle-containing layer is from 80% to 140% relative to an
average particle diameter of the conductive particles. <6>
The anisotropic conductive film according to any one of <3>
to <5>, wherein a ratio of a mass of the first crystalline
resin to a mass of the second crystalline resin is from 25:75 to
75:25. <7> The anisotropic conductive film according to any
one of <4> to <6>, wherein a ratio (X):(Y) is from
25:75 to 75:25, where (X) is the sum of a mass of the first
crystalline resin and a mass of the second crystalline resin and
(Y) is a mass of the amorphous resin. <8> The anisotropic
conductive film according to any one of <4> to <7>,
wherein the first crystalline resin contains crystalline polyester,
the second crystalline resin contains a crystalline polyurethane
resin, and the amorphous resin contains an amorphous polyester
resin. <9> The anisotropic conductive film according to any
one of <1> to <8>, wherein an average particle diameter
of the conductive particles is from 2 .mu.m to 40 .mu.m. <10>
A connecting method for anisotropically conductively connecting a
terminal of a first electronic component and a terminal of a second
electronic component, the connecting method including:
[0019] arranging the conductive particle-containing layer of the
anisotropic conductive film according to any one of <1> to
<9> on the terminal of the second electronic component to
perform a first arrangement;
[0020] arranging the first electronic component on the conductive
particle-containing layer to bring the terminal of the first
electronic component into contact with the conductive
particle-containing layer to perform a second arrangement; and
[0021] heating and pressing the first electronic component with a
heat-press member.
<11> The connecting method according to <10>, wherein a
contact area when the terminal of the first electronic component
and the terminal of the second electronic component are
anisotropically conductively connected is 100 mm.sup.2 or greater.
<12> A joined structure connected by the connecting method
according to <10> or <11>.
Advantageous Effects of the Invention
[0022] The present invention can solve the aforementioned various
problems in the art and achieve the aforementioned object, and can
provide an anisotropic conductive film, which can assure excellent
conduction at a center part of connection, particularly with a
relatively large area, with maintaining sufficient connection
resistance, contains a conductive particle-containing film having
sufficient adhesion to a substrate that is a target for connection,
has sufficient releasability and adhesion between the conductive
particle-containing layer and a release film, and has excellent
temporary-fixing properties between facing parts, as well as
providing a connecting method and a joined structure both using the
anisotropic conductive film.
DESCRIPTION OF EMBODIMENTS
(Anisotropic Conductive Film)
[0023] The anisotropic conductive film of the present invention
includes at least a conductive particle-containing layer, and may
further include other layers or other components, such as a
releasable base, according to the necessity.
[0024] The anisotropic conductive film is an anisotropic conductive
film for anisotropically conductively connecting a terminal of a
first electronic component and a terminal of a second electronic
component.
[0025] The anisotropic conductive film has the following
characteristics.
[0026] In differential scanning calorimetry where endothermic peak
temperatures are measured under conditions that a measuring
temperature range is from 10.degree. C. to 250.degree. C. and a
heating speed is 10.degree. C./min, T2 is 30.degree. C. or higher,
and T4-T2 is greater than 0.degree. C. but 80.degree. C. or less,
where the conductive particle-containing layer has two endothermic
peaks, T2 is a temperature of the endothermic peak present at a
lower temperature side, and T4 is a temperature of the endothermic
peak present at a higher temperature side.
[0027] The anisotropic conductive film of the present invention
having the aforementioned characteristics is an anisotropic
conductive film, which assures excellent conduction at a center
part of connection with a relatively large area, and has excellent
temporary-fixing properties.
[0028] As for a preferable embodiment when a below-mentioned joined
structure is produced using the anisotropic conductive film of the
present invention, there is an embodiment where T2 and T4 are set
to satisfy the relationship represented by the following formula
(1) in differential scanning calorimetry performed under conditions
that the measuring temperature range is from 10.degree. C. to
250.degree. C. and the heating speed is 10.degree. C./min, where T1
is room temperature at which the anisotropic conductive film is
used, T3 is a temperature for temporary-bonding, and T5 is a
temperature for bonding.
T1<T2<T3<T4<T5 (1)
[0029] According to the aforementioned embodiment, part of the
material in the conductive particle-containing layer is melted at
the temporary-bonding temperature because of the presence of T2.
Therefore, the conductive particle-containing layer generates
tackiness to improve temporary-fixing properties. The crystalline
material in the conductive particle-containing layer is in a
crystalline state at T1, and therefore the conductive
particle-containing layer does not have tackiness or have only
slight tackiness to make handling of the conductive
particle-containing layer easy, leading to excellent handling.
[0030] T4 is present at a temperature lower than T5. It has been
difficult to achieve conduction at a center part of a large area
with a reaction-type anisotropic conductive film. Since T4 is
present at a temperature lower than T5, the adhesive layer-forming
component of the anisotropic conductive film of the present
invention can be flown outside the terminal region to crush
conductive particles, and therefore excellent conduction can be
assured.
[0031] In order to obtain the anisotropic conductive film having
the desired T2 and T4, crystalline materials having endothermic
peaks at desired temperatures may be blended. The crystalline
materials are described later.
<Differential Scanning Calorimetry (DSC)>
[0032] When a measurement of DSC is performed under the following
conditions, an endothermic onset temperature, an endothermic peak
temperature, and an endothermic value at the time of heating can be
determined.
Measuring Device: Q100, manufactured by TA Instruments Japan
Inc.
Measuring Sample: 5 mg
[0033] Measuring Temperature Range: from 10.degree. C. to
250.degree. C.
Heating Speed: 10.degree. C./min
<Conductive Particle-Containing Layer>
[0034] The conductive particle-containing layer contains at least
an adhesive layer-forming component and conductive particles, and
may further contain other components according to the
necessity.
<<Adhesive Layer-Forming Component>>
[0035] The adhesive layer-forming component is not particularly
limited and may be appropriately selected depending on the intended
purpose. Examples of the adhesive layer-forming component include a
crystalline resin and an amorphous resin.
[0036] Among the above-listed examples, use of the crystalline
resin and the amorphous resin in combination is preferable because
connection with electronic components can be achieved at a low
temperature for a short period of time while sufficiently
maintaining connection resistance of the anisotropic conductive
film. Moreover, in a case where two or more crystalline resins are
used as the crystalline resin, and the two or more crystalline
resins and the amorphous resin are used in combination, such use of
the two or more crystalline resins and the amorphous resin in
combination is more preferable because excellent conduction is
assured at a center part of connection, particularly, with a
relatively large area, with maintaining sufficient connection
resistance of the anisotropic conductive film, excellent
temporary-fixing properties are obtained, and connection of
electronic components can be realized at a low temperature for a
short period. --Crystalline Resin--
[0037] The crystalline resin is not particularly limited and may be
appropriately selected depending on the intended purpose, expect
that the crystalline resin is a resin containing a crystalline
region. Examples of the crystalline resin include a polyester
resin, a polyurethane resin, and a polyolefin resin. Whether the
resin is the crystalline resin can be confirmed, for example, by
the presence of an endothermic peak observed during heating in
differential scanning calorimetry.
[0038] In the present invention, two or more crystalline resins are
contained to obtain the anisotropic conductive film having the
desired T2 and T4.
[0039] A particularly preferable embodiment is that a first
crystalline resin among the two or more crystalline resins is a
crystalline polyester resin, and a second crystalline resin among
the crystalline resins is a crystalline polyurethane resin.
[0040] In the present invention, another crystalline resin may be
further contained in addition to the first crystalline resin and
the second crystalline resin. For example, the aforementioned
another crystalline resin may be a crystalline polyester resin
different from the first crystalline resin, a crystalline
polyurethane resin different from the second crystalline resin, or
another crystalline resin, such as a crystalline polyolefin resin,
that is not either a crystalline polyester resin or a crystalline
polyurethane resin.
[0041] Examples of the polyester resin include a polyethylene
terephthalate resin and a polybutylene terephthalate resin.
[0042] Examples of the polyolefin resin include a polyethylene
resin, a polypropylene resin, and a polybutylene resin.
[0043] A ratio of a mass (g) of the first crystalline resin to a
mass (g) of the second crystalline resin is preferably from 25:75
to 75:25, more preferably from 30:70 to 70:30.
--Amorphous Resin--
[0044] Examples of the amorphous resin includes the same resins
listed as examples in the description of the crystalline resin.
[0045] In the case where the amorphous resin and the crystalline
resin are used in combination in the present invention, the same
kind of resins are preferably used as the amorphous resin and the
crystalline resin in combination. For example, preferred are a
combination of a crystalline polyester resin and an amorphous
polyester resin, a combination of a crystalline polyurethane resin
and an amorphous polyurethane resin, and a combination of a
crystalline polyolefin resin and an amorphous polyolefin resin.
When the same kind of resins are used as the crystalline resin and
the amorphous resin in combination, the crystalline resin and the
amorphous resin are mixed to create a state where the crystalline
resin is easily dissolved in a solvent, and therefore a conductive
particle-containing layer homogeneously containing the crystalline
resin can be obtained.
[0046] The obtained conductive particle-containing layer can
achieve connection at a low temperature for a short period. The
reason for this is assumed as follows. The conductive
particle-containing layer is quickly solidified due to the
crystalline resin, when the heated state is returned to a normal
temperature, after heating and softening the conductive
particle-containing layer.
[0047] In the case where two or more crystalline resins are
contained in the conductive particle-containing layer in the
present invention, and a crystalline polyester resin and a
crystalline polyurethane resin are contained as the crystalline
resins, either an amorphous polyester resin or an amorphous
polyurethane resin is preferably used as the amorphous resin, but
use of the amorphous polyester resin as the amorphous resin is more
preferable because flexibility is imparted to a resulting film at
room temperature.
[0048] A ratio of the sum (X) (g) of a mass of the first
crystalline resin and a mass of the second crystalline resin to a
mass (Y) (g) of the amorphous resin is preferably (X):(Y)=25:75 to
75:25, and more preferably (X):(Y)=40:60 to 60:40.
<<Conductive Particles>>
[0049] The conductive particles are not particularly limited and
may be appropriately selected depending on the intended purpose.
Examples of the conductive particles include metal particles and
metal-coated resin particles.
[0050] The metal particles are not particularly limited and may be
appropriately selected depending on the intended purpose. Examples
of the metal particles include nickel, cobalt, silver, copper,
gold, palladium, and solder. These may be used alone or in
combination.
[0051] Among them, preferred are nickel, silver, and copper.
Surfaces of these metal particles may be coated with gold or
palladium for the purpose of preventing surface oxidization.
Moreover, metal particles, to each surface of which metal
protrusions or an insulating coating film formed of an organic
material may be provided, may be used.
[0052] The metal-coated resin particles are not particularly
limited and may be appropriately selected depending on the intended
purpose, expect that the metal-coated resin particles are
particles, in each of which a surface of a resin particle is
covered with a metal. Examples of the metal-coated resin particles
include particles, in each of which a surface of a resin particle
is covered with at least one metal selected from the group
consisting of nickel, silver, solder, copper, gold, and palladium.
Moreover, metal-coated resin particles, to each surface of which
metal protrusions or an insulating coating film formed of an
organic material may be provided, may be used. In case of
connection considering low resistance, use of particles, in each of
which a surface of a resin particle is covered with silver, is
preferable.
[0053] A method for covering the resin particles with a metal is
not particularly limited and may be appropriately selected
depending on the intended purpose. Examples of the method include
electroless plating and sputtering.
[0054] A material of the resin particles is not particularly
limited and may be appropriately selected depending on the intended
purpose. Examples of the material include a styrene-divinylbenzene
copolymer, a benzoguanamine resin, a crosslinked polystyrene resin,
an acrylic resin, and a styrene-silica composite resin.
[0055] The conductive particles are not particularly limited as
long as they have conductivity when anisotropic conductive
connection is made. For example, particles, in each of which an
insulating coating film is provided on a metal particle, are the
aforementioned conductive particles, as long as the particles are
deformed to expose the metal particles at the time when anisotropic
conductive connection is made.
[0056] The average particle diameter of the conductive particles is
not particularly limited and may be appropriately selected
depending on the intended purpose. The average particle diameter is
preferably from 2 .mu.m to 40 .mu.m, more preferably from 5 .mu.m
to 30 .mu.m, even more preferably from 10 .mu.m to 25 .mu.m, and
particularly preferably from 10 .mu.m to 20 .mu.m.
[0057] The average particle diameter is an average value of
particle diameters arbitrarily measured on 10 conductive
particles.
[0058] For example, the particle diameters can be measured by
observing under a scanning electron microscope.
[0059] An amount of the conductive particles is not particularly
limited and may be appropriately selected depending on the intended
purpose.
<Releasable Base>
[0060] The releasable base is not particularly limited, as long as
the releasable base is a film that can be peeled off from the
conductive particle-containing layer at the time of
temporary-bonding. For example, a releasable base having a contact
angle of 80.degree. or greater relative to water can be used.
[0061] Moreover, examples of the releasable base include a
silicone-based film, a fluorine-based film, and PET, PEN, and
glassine paper treated with a releasing agent, such as a
silicone-based releasing agent and a fluorine-based releasing
agent. Among the above-listed examples, a silicone-based releasable
base is preferable.
[0062] The average thickness of the releasable base is not
particularly limited and may be appropriately selected depending on
the intended purpose. The average thickness of the releasable base
is preferably from 12 .mu.m to 75 .mu.m.
<Production Method of Anisotropic Conductive Film>
[0063] In the present invention, the anisotropic conductive film
may be produced by the following steps.
[0064] The anisotropic conductive film is produced by: a varnish
preparation step of dissolving the adhesive layer-forming component
in a solvent to prepare a varnish; an anisotropic conductive
composition preparation step of adding conductive particles to the
varnish to obtain an anisotropic conductive composition; and a step
of applying the anisotropic conductive composition onto a
releasable base and drying the anisotropic conductive
composition.
[0065] The solvent used for the adhesive layer-forming component is
not particularly limited and may be appropriately selected
depending on the intended purpose. For example, a mixed solvent of
methyl ethyl ketone, toluene, and cyclohexanone (methyl ethyl
ketone:toluene:cyclohexanone=50:40:10 (mass ratio)) or a mixed
solvent of toluene and ethyl acetate (toluene:ethyl acetate=50:50
(mass ratio)) may be used.
<First Electronic Component and Second Electronic
Component>
[0066] The first electronic component and the second electronic
component are not particularly limited and may be appropriately
selected depending on the intended purpose, except that the first
electronic component and the second electronic component are
electronic components having terminals, which are to be targets for
anisotropic conductive connection using the anisotropic conductive
film. Examples of the first electronic component and the second
electronic component include glass substrates, flexible substrates,
rigid substrates, integrated circuit (IC) chips, tape automated
bonding (TAB), and liquid crystal panels. Examples of the glass
substrates include Al wire-formed glass substrates, and ITO
wire-formed glass substrates. Examples of the IC chips include IC
chips for controlling liquid crystal displays used in flat panel
displays (FPD).
[0067] The average thickness of the conductive particle-containing
layer in the anisotropic conductive film is not particularly
limited and may be appropriately selected depending on the intended
purpose. The average thickness of the conductive
particle-containing layer is preferably from 5 .mu.m to 50 .mu.m,
and more preferably from 8 .mu.m to 16 .mu.m.
[0068] In the present invention, the average thickness of the
conductive particle-containing layer is more preferably set
considering the average particle diameter of the conductive
particles. As for the average thickness of the conductive
particle-containing layer, the average thickness may be from 80% to
140% relative to the average particle diameter of the conductive
particles.
(Connecting Method)
[0069] The connecting method of the present invention includes at
least a first arrangement step, a second arrangement step, and a
heat press step, and may further include other steps, such as a
release step of a releasable base, according to the necessity.
[0070] The connecting method is a method for anisotropically
conductively connecting a terminal of a first electronic component
and a terminal of a second electronic component.
[0071] The first electronic component and the second electronic
component are not particularly limited and may be appropriately
selected depending on the intended purpose. Examples of the first
electronic component and the second electronic component include
the first electronic components and the second electronic
components listed as examples in the description of the anisotropic
conductive film of the present invention.
[0072] Use of the anisotropic conductive film of the present
invention can assure excellent conduction at a center part through
connection with a large area. Accordingly, use of the anisotropic
conductive film of the present invention can excellently connect a
terminal of a first electronic component and a terminal of a second
electronic component together when a contact area for anisotropic
conductive connection between the terminal of the first electronic
component and the terminal of the second electronic component is
100 mm.sup.2 or greater.
<First Arrangement Step>
[0073] The first arrangement step is not particularly limited and
may be appropriately selected depending on the intended purpose,
except that the first arrangement step is arranging the conductive
particle-containing layer of the anisotropic conductive film of the
present invention on a terminal of the second electronic
component.
<Second Arrangement Step>
[0074] The second arrangement step is not particularly limited and
may be appropriately selected depending on the intended purpose,
except that the second arrangement step is arranging the first
electronic component on the conductive particle-containing layer to
bring a terminal of the first electronic component into contact
with the conductive particle-containing layer.
<Heat Press Step>
[0075] The heat press step is not particularly limited and may be
appropriately selected depending on the intended purpose, except
that the heat press step is heating and pressing the first
electronic component with a heat press member.
[0076] Examples of the heat press member include a press member
having a heating system. Examples of the press member having a
heating system include a heat tool.
[0077] A temperature of the heating is not particularly limited and
may be appropriately selected depending on the intended purpose.
The temperature is preferably from 100.degree. C. to 140.degree.
C.
[0078] Pressure of the pressing is not particularly limited and may
be appropriately selected depending on the intended purpose. The
pressure is preferably from 2 MPa to 6 MPa.
[0079] A duration of the heating and pressing is not particularly
limited and may be appropriately selected depending on the intended
purpose. The duration is preferably from 2 minutes to 20
minutes.
<Other Steps>
<<Releasing Step of Releasable Base>>
[0080] Examples of the aforementioned other steps include a
releasing step of a releasable base containing releasing the
releasable base of the anisotropic conductive film from the
conductive particle-containing layer.
(Joined Structure)
[0081] The joined structure of the present invention is not limited
as long as the joined structure is a joined structure connected by
the aforementioned connecting method. The joined structure includes
at least a first electronic component, a second electronic
component, and a conductive particle-containing layer, and may
further include other members according to the necessity.
EXAMPLES
[0082] The present invention will be more specifically explained
through Examples and Comparative Examples hereinafter, but the
present invention is not limited to Examples. Note that, "part(s)"
denotes "part(s) by mass."
Example 1
<Production of Anisotropic Conductive Film>
[0083] A solution was produced by mixing and stirring 80 parts by
mass of ARONMELT PES-111EE (manufactured by TOAGOSEI CO., LTD., a
crystalline resin a main component of which was a crystalline
polyester resin) serving as a first crystalline resin A1, 40 parts
by mass of DESMOCOLL 540 (manufactured by Sumika Bayer Urethane
Co., Ltd., a crystalline linear polyurethane resin) serving as a
second crystalline resin A2, 80 parts by mass of ELITEL UE3500
(manufactured by UNITIKA LTD., an amorphous polyester resin, weight
average molecular weight: 30,000) serving as an amorphous resin A3,
and 400 parts by mass of a mixed solvent (methyl ethyl ketone
(MEK):toluene:cyclohexanone=50:40:10 (mass ratio)), to thereby
obtain a varnish mixture.
[0084] Subsequently, 5 parts by mass of spherical Ag-plated resin
particles having the average particle diameter of 10 .mu.m
(conductive particles obtained by the following production method)
was added to the varnish mixture to obtain an anisotropic
conductive composition.
[0085] The obtained anisotropic conductive composition was applied
onto a polyethylene terephthalate (PET) film treated with a
silicone-based releasing agent and having the average thickness of
50 .mu.m in a manner that the average thickness of the anisotropic
conductive composition after drying was to be 12 .mu.m. The applied
anisotropic conductive composition was dried at 70.degree. C. for
10 minutes to produce an anisotropic conductive film. --Production
of Silicone-Based Releasing Agent Treated Film--
[0086] To a mixed solvent containing 40 parts by mass of toluene
and 47 parts by mass of methyl ethyl ketone, 13 parts by mass of an
addition-reactable silicone solution (product name "KS-847"
manufactured by Shin-Etsu Chemical Co., Ltd., silicone
concentration: 30% by mass) and 0.3 parts by mass of a platinum
curing catalyst (product name "PL-50T" manufactured by Shin-Etsu
Chemical Co., Ltd.) were added to prepare a coating liquid for a
releasing layer.
[0087] The coating liquid for a releasing layer was applied onto a
PET film, both surfaces of which had been untreated, to give the
average thickness of 50 .mu.m, and the applied coating liquid was
dried to thereby obtain a silicone-based release film.
[0088] Note that, a coil bar was used for the application of the
coating liquid. As for the curing of the coated layer, the entire
coated layer was heated at 160.degree. C. for 1 minute. The average
thickness of the silicone-based releasing agent after being dried
was 0.1 .mu.m. --Production of Conductive Particles--
--Production of Divinyl Benzene-Based Resin Particles--
[0089] To a solution, in which a blending ratio of divinyl benzene,
styrene, and butyl methacrylate was adjusted, benzoyl peroxide was
added as a polymerization initiator. The resultant was heated with
homogeneously stirring at high speed to perform a polymerization
reaction, to thereby obtain a particle dispersion liquid. The
particle dispersion liquid was subjected to filtration, followed by
being dried under reduced pressure, to thereby obtain a block body
that was an aggregated body of the particles. Moreover, the block
body was ground to obtain divinyl benzene-based resin
particles.
--Silver Plating of Resin Particles--
[0090] To a solution prepared by dissolving 4.25 g of silver
nitrate serving as a silver salt in 625 mL of pure water at room
temperature, 15 g of benzimidazole serving as a reducing agent was
added. After confirming that the initially generated sediment was
completely dissolved, 5 g of succinic acid imide and 3 g of citric
acid monohydrate were dissolved therein as complexing agents.
Thereafter, 13 g of glyoxylic acid serving as a crystal-adjusting
agent was added thereto and was completely dissolved, to thereby
prepare an electroless silver plating solution.
[0091] Subsequently, the divinylbenzene-based resin particles
obtained above were added to the electroless silver plating
solution, and the resultant was heated with stirring and the
temperature of the solution was maintained to 50.degree. C.
Thereafter, the particles therein were separated by filtration with
Buchner funnel, and the separated particles were dried by means of
a vacuum drier at 80.degree. C. for 2 hours, to thereby obtain
spherical Ag-plated resin particles (conductive particles) having
the average particle diameter of 10 .mu.m.
<Differential Scanning Calorimetry (DSC)>
[0092] A measurement of DSC was performed on the conductive
particle-containing layer of the above-obtained anisotropic
conductive film of the present invention under the following
conditions to determine endothermic peak temperatures (T2 and T4)
at the time of heating. The results are presented in Table 1-1. In
the case where it was difficult to recognize an endothermic peak,
the temperature, at which the endothermic value was the maximum
between two points, the endothermic onset temperature and the
endothermic end temperature, in the endothermic temperature region,
was determined as an endothermic peak temperature.
Measuring Device: Q100, manufactured by TA Instruments Japan
Inc.
Measuring Sample: 5 mg
Measuring Temperature Range: 10.degree. C. to 250.degree. C.
Heating Speed: 10.degree. C./min
<Evaluation of Laminating Properties>
[0093] A PET film having the average thickness of 25 .mu.m was set
on a hot stage a temperature of which was adjusted to 70.degree. C.
The anisotropic conductive film of the present invention cut into a
size of 50 mm.times.25 mm was arranged on the PET film. After
pressing the stuck of the PET film and the anisotropic conductive
film by running a hand roller of 5 kg over and back twice, the
releasable base (silicone-based release-treated film) was peeled
off from the anisotropic conductive film. The evaluation was
performed based on the following criteria. A result is presented in
Table 1-1.
[Evaluation Criteria]
[0094] A: The anisotropic conductive film was uniformly laminated
on the PET film without causing bending, creasing, or missing of
the conductive particle-containing layer, when the releasable base
was peeled off. B: Although bending, creasing, or missing of the
conductive particle-containing layer was caused when the releasable
base was peeled off, the laminating itself could be performed. C:
Bending, creasing, or missing of the conductive particle-containing
layer was caused when the releasable base was peeled off, and the
anisotropic conductive film was not uniformly laminated on the PET
film.
<Evaluation of Temporary-Fixing Properties>
[0095] A PET film having the average thickness of 25 .mu.m was set
on a hot stage a temperature of which was adjusted to 70.degree. C.
The anisotropic conductive film of the present invention cut into a
size of 50 mm.times.25 mm was arranged on the PET film. After
pressing the stuck of the PET film and the anisotropic conductive
film by running a hand roller of 5 kg over and back twice, the
releasable base (silicone-based release-treated film) was peeled
from the anisotropic conductive film.
[0096] A three-layer structure flexible printed circuit board (may
be referred to as a "FPC" hereinafter), in which the average
thickness of the terminal part was 25 .mu.m, was laminated on the
resultant. Thereafter, the hand roller of 5 kg was again run the
FPC over and back twice for the purpose of temporarily fixing the
PET film and the FPC, to thereby produce a temporary-adhered
sample. The evaluation was performed based on the following
criteria. The result is presented in Table 1-1.
[Evaluation Criteria]
[0097] A: There was no problem in the temporary adhesion between
the FPC and the PET film, and the FPC and the PET film were not
detached from each other. C: It was difficult to temporarily adhere
the FPC and the PET film together, and a temporary-adhered sample
could not be produced because the FPC and the PET film were
detached from each other.
<Production of Joined Structure>
[0098] Two joined structures, Test Pieces A and B, were produced in
the following manner. --Test Piece A--
[0099] A three-layer structure FPC (an area of a terminal part: 20
mm.times.5 mm=100 mm.sup.2), in which the average thickness of the
terminal part was 25 .mu.m, was used as a target member-1.
[0100] A PET film having the average thickness of 25 .mu.m was used
as a target member-2. --Test Piece B--
[0101] A three-layer structure FPC (an area of a terminal part: 50
mm.times.25 mm=1,250 mm.sup.2), in which the average thickness of
the terminal part was 25 .mu.m, was used as a target member-1.
[0102] A PET film having the average thickness of 25 .mu.m was used
as a target member-2.
[0103] A temporary-fixed sample in combination of Test Piece A or
Test Piece B was prepared in the same manner as the preparation of
the temporary-adhered sample. The temporary-fixed sample was heated
and pressed from the side of the target member-1 under the
following heat press conditions to thereby obtain a joined
structure.
Set temperature of heat source: 110.degree. C. Set temperature of
glass stage: 90.degree. C. Thrust: 500 kgf/1,250 mm.sup.2 Press
duration: 3 minutes <<Evaluation for Crushed Particles at
in-Plane Center Part>>
[0104] A state of crushed conductive particles at a center part of
a sample piece was confirmed on the obtained two joined structures
(Test Piece A and Test Piece B) by setting each test piece on a
metallurgical microscope. The evaluation was performed based on the
following criteria. The result is presented in Table 1-1.
[Evaluation Criteria]
[0105] A: The conductive particles were crushed, and particle
diameters along a plane direction were 1.2 times or greater the
particle diameters before being crushed. B: The conductive
particles were crushed, but particle diameters along a plane
direction were 1.1 times or greater but less than 1.2 times the
particle diameters before being crushed. C: The conductive
particles were crushed, but particle diameters along a plane
direction were less than 1.1 times the particle diameters before
being crushed.
<<Comprehensive Evaluation>>
[0106] The three results of the aforementioned evaluation of
laminating properties, evaluation of temporary-fixing properties,
and evaluation of crushed particles at an in-plane center part were
comprehensively evaluated based on the following evaluation
criteria. The result is presented in Table 1-1.
[Evaluation Criteria]
[0107] A: All of the three evaluations were A. B: Among the three
evaluations, there was no C, and one or more B. C: Among the three
evaluations, there was one or more C.
Examples 2 to 7
[0108] Anisotropic conductive films and joined structures were each
produced in the same manner as in Example 1, except that an amount
of each adhesive layer-forming component was changed as depicted in
Table 1-1.
[0109] The obtained anisotropic conductive films and joined
structures were evaluated in the same manner as in Example 1. The
results are presented in Table 1-1.
Example 8
[0110] An anisotropic conductive film and a joined structure were
produced in the same manner as in Example 1, except that DESMOCOLL
540 serving as the second crystalline resin A2 was replaced with
DESMOCOLL 530 (manufactured by Sumika Bayer Urethane Co., Ltd., a
crystalline linear polyurethane resin), and the average thickness
of the conductive particle-containing layer after being dried was
changed to a thickness depicted in Table 1-2.
[0111] The obtained anisotropic conductive film and joined
structure were evaluated in the same manner as in Example 1. The
results are presented in Table 1-2.
Example 9
[0112] An anisotropic conductive film and a joined structure were
produced in the same manner as in Example 1, except that ARONMELT
PES-111EE serving as the first crystalline resin A1 was replaced
with VYLON GA-6400 (manufactured by TOYOBO CO., LTD., a crystalline
resin a main component of which was a crystalline polyester
resin).
[0113] The obtained anisotropic conductive film and joined
structure were evaluated in the same manner as in Example 1. The
results are presented in Table 1-2.
Examples 10 and 11
[0114] Anisotropic conductive films and joined structures were each
produced in the same manner as in Example 1, except that the
average thickness of the conductive particle-containing layer after
being dried was changed to a thickness depicted in Table 1-2.
[0115] The obtained anisotropic conductive films and joined
structures were evaluated in the same manner as in Example 1. The
results are presented in Table 1-2.
Examples 12 to 15
[0116] Anisotropic conductive films and joined structures were
produced in the same manner as in Example 1, except that an amount
of each adhesive layer-forming component was changed as depicted in
Table 1-3.
[0117] The obtained anisotropic conductive films and joined
structures were evaluated in the same manner as in Example 1. The
results are presented in Table 1-3.
Comparative Example 1
[0118] An anisotropic conductive film and a joined structure were
produced in the same manner as in Example 1, except that DESMOCOLL
540 serving as the second crystalline resin A2 was replaced with
NIPPOLAN 5196 (manufactured by Nippon Polyurethane Industry Co.,
Ltd., a polyurethane resin of a polycarbonate skeleton).
[0119] The obtained anisotropic conductive film and joined
structure were evaluated in the same manner as in Example 1. In
Comparative Example 1, laminating and temporary-fixing could not be
achieved, and therefore the test for the crushed particles at the
in-plane center part could not be performed. The results are
presented in Table 1-4.
Comparative Example 2
[0120] An anisotropic conductive film and a joined structure were
produced in the same manner as in Example 1, except that DESMOCOLL
540 serving as the second crystalline resin A2 was replaced with
DESMOCOLL 176 (manufactured by Sumika Bayer Urethane Co., Ltd., a
crystalline linear polyurethane resin).
[0121] The obtained anisotropic conductive film and joined
structure were evaluated in the same manner as in Example 1. The
results are presented in Table 1-4.
Comparative Example 3
[0122] An anisotropic conductive film and a joined structure were
produced in the same manner as in Example 1, except that ARONMELT
PES-111EE serving as the first crystalline resin A1 was replaced
with ARONMELT PES126E (manufactured by TOAGOSEI CO., LTD., a
crystalline resin a main component of which was a crystalline
polyester resin).
[0123] The obtained anisotropic conductive film and joined
structure were evaluated in the same manner as in Example 1. The
results are presented in Table 1-4.
TABLE-US-00001 TABLE 1-1 Ex. Ex. Ex. Ex. Ex. Ex. Ex. 1 2 3 4 5 6 7
First crystalline ARONMELT 80 60 40 70 15 30 80 resin A1 PES-111EE
Second DESMOCOLL 40 60 80 70 15 30 40 crystalline 540 resin A2
Amorphous ELITEL 80 80 80 60 70 140 80 resin A3 UE3500 Conductive
(.phi.) 10 .mu.m 5 5 5 5 5 5 5 particles Average thickness of
conductive 12 12 12 12 12 12 12 particle-containing layer (.mu.m)
T1.degree. C. Used room 23 23 23 23 23 23 23 temperature T2.degree.
C. Endothermic peak 46 46 46 46 46 46 46 temperature at low
temperature side T3.degree. C. Temporary-bonding 70 70 70 70 70 70
70 temperature T4.degree. C. Endothermic peak 108 108 108 108 108
108 108 temperature at high temperature side T5.degree. C. Bonding
110 110 110 110 110 110 110 temperature T4 - T2 (endothermic peak
62 62 62 62 62 62 62 temperature difference) Laminating properties
A A A A A A A Temporary-fixing properties A A A A A A A Crushed
Test Piece A A A A A A A A particles at Test Piece B A A A A A A A
in-plane center part Comprehensive evaluation A A A A A A A
TABLE-US-00002 TABLE 1-2 Ex. 8 Ex. 9 Ex. 10 Ex. 11 First ARONMELT
80 -- 80 80 crystalline PES-111EE resin A1 VYLON GA-6400 -- 80 --
-- Second DESMOCOLL 40 -- -- -- crystalline 530 resin A2 DESMOCOLL
-- 40 40 40 540 Amorphous ELITEL UE3500 80 80 80 80 resin A3
Conductive (.phi.) 10 .mu.m 5 5 5 5 particles Average thickness of
conductive 10 12 15 7 particle-containing layer (.mu.m) T1 .degree.
C. Used room temperature 23 23 23 23 T2 .degree. C. Endothermic
peak 43 46 46 46 temperature at low temperature side T3 .degree. C.
Temporary-bonding 70 70 70 70 temperature T4 .degree. C.
Endothermic peak 108 74 108 108 temperature at high temperature
side T5 .degree. C. Bonding temperature 110 110 110 110 T4 - T2
(endothermic 65 28 62 62 peak temperature difference) Laminating
properties A A A B Temporary-fixing properties A A A A Crushed Test
A A A A particles at Piece A in-plane Test A A B A center part
Piece B Comprehensive A A B B evaluation
TABLE-US-00003 TABLE 1-3 Ex. 12 Ex. 13 Ex. 14 Ex. 15 First
crystalline ARONMELT 24 76 39 121 resin A1 PES-111EE Second
DESMOCOLL 24 76 121 39 crystalline resin 540 A2 Amorphous ELITEL
UE3500 152 48 80 80 resin A3 Conductive (.phi.) 10 .mu.m 5 5 5 5
particles Average thickness of conductive 12 12 12 12
particle-containing layer (.mu.m) T1 .degree. C. Used room
temperature 23 23 23 23 T2 .degree. C. Endothermic peak 46 46 46 46
temperature at low temperature side T3 .degree. C.
Temporary-bonding 70 70 70 70 temperature T4 .degree. C.
Endothermic peak 108 108 108 108 temperature at high temperature
side T5 .degree. C. Bonding temperature 110 110 110 110 T4 - T2
(endothermic peak 62 62 62 62 temperature difference) Laminating
properties A A A B Temporary-fixing properties A A A A Crushed
particles Test Piece A A A A A at in-plane center Test Piece B B B
B A part Comprehensive evaluation B B B B
TABLE-US-00004 TABLE 1-4 Comp. Comp. Comp. Ex. 1 Ex. 2 Ex. 3 First
crystalline ARONMELT 80 80 -- resin A1 PES-111EE ARONMELT -- -- 80
PES126E Second crystalline DESMOCOLL -- -- 40 resin A2 540
DESMOCOLL -- 40 -- 176 Amorphous resin ELITEL UE3500 80 80 80 A3
NIPPOLAN 5196 40 -- -- Conductive (.phi.) 10 .mu.m 5 5 5 particles
Average thickness of conductive 12 12 12 particle-containing layer
(.mu.m) T1 .degree. C. Used room temperature 23 23 23 T2 .degree.
C. Endothermic peak -- -26 46 temperature at low temperature side
T3 .degree. C. Temporary-bonding 70 70 70 temperature T4 .degree.
C. Endothermic peak 108 108 135 temperature at high temperature
side T5 .degree. C. Bonding temperature 110 110 110 T4 - T2
(endothermic peak 108 134 89 temperature difference) Laminating
properties C C A Temporary-fixing properties C A A Crushed
particles Test Could not be A C at in-plane center Piece A tested
part Test Could not be A C Piece B tested Comprehensive evaluation
C C C
[0124] A unit of a blended amount (equal to an amount) of each
component in Tables 1-1 to 1-4 is parts by mass.
[0125] It was confirmed from Examples 1 to 15 that the anisotropic
conductive film of the present invention could assure excellent
conduction at a center part, especially for connection with a
relatively large area, with maintaining sufficient connection
resistance, and had excellent laminating properties at the time of
temporary-bonding, excellent temporary-adhesion, and excellent
temporary-fixing properties.
[0126] It was confirmed from the results of Examples 1 to 7
comparing with Examples 10 and 11 that the excellent results could
be obtained when the average thickness of the anisotropic
conductive film was from 80% to 140% relative to the average
particle diameter of the conductive particles.
[0127] Moreover, it was confirmed from the results of Examples 1 to
7 comparing with Examples 14 and 15 that even more excellent
conduction could be achieved at a center part for connection with a
large area and more excellent temporary-fixing properties could be
obtained when the ratio of the mass of the first crystalline resin
to the mass of the second crystalline resin was from 25:75 to
75:25.
[0128] Furthermore, it was confirmed from the results of Examples 1
to 7 comparing with Examples 12 and 13 that even more excellent
conduction could be achieved at a center part for connection with a
large area and more excellent temporary-fixing properties could be
obtained when the ratio of the sum of the mass (X) of the first
crystalline resin and the mass of the second crystalline resin to
the mass (Y) of the amorphous resin was (X):(Y)=25:75 to 75:25.
INDUSTRIAL APPLICABILITY
[0129] The anisotropic conductive film of the present invention can
assure excellent conduction at a center part of connection,
particularly with a relatively large area, with maintaining
sufficient connection resistance, and has excellent
temporary-fixing properties, where a conductive particle-containing
film contained in the anisotropic conductive film has appropriate
adhesion to a substrate that is a target for connection, and the
conductive particle-containing layer and a release film have
sufficient releasability and adhesion. Accordingly, the anisotropic
conductive film can be suitably used as a connecting material when
a terminal of a substrate and a terminal of an electronic component
are anisotropically conductively connected to produce a joined
structure.
* * * * *